(Reuters) - Walmart is bringing back layaway a month early, giving U.S. shoppers under economic pressure more time to pay for holiday gifts, and will refund related fees with gift cards once payments are completed.

Layaway, which allows a customer to keep a product on hold at the store and pay for it over time, helped boost holiday sales for Walmart when it brought the service back in 2011 after a five-year hiatus.

Offering layaway helps retailers such as Wal-Mart Stores Inc win over shoppers without access to credit. Walmart U.S., Wal-Mart's largest unit, also offers check cashing and other services as it tries to appeal to shoppers without bank accounts.

Walmart's holiday layaway service will begin on September 16, it said on Monday. Last year it began on October 17.

"The customer was saying if they had two more pay cycles that really would be helpful for them," said Walmart U.S. Chief Merchandising and Marketing Officer Duncan Mac Naughton.

The longer layaway plan comes after Wal-Mart said it saw more incidents of consumers living paycheck-to-paycheck during the latest quarter.

Extending the program could drive traffic and sales, if shoppers who come back to make payments more frequently buy other items during those visits.

In the past, Walmart has said about 85 percent of transactions in its stores are paid for with cash. Earlier this year it began allowing shoppers to place orders online and pay for them in a store with cash.

For now, layaway will remain an in-store service only and will be offered only for the holiday season, Mac Naughton said.

Still, the company is making a limited social media push. Customers who "like" their local Walmart store on Facebook can use layaway two days early, on Friday, September 14.

Under this year's plan, customers must pay a $15 fee to open a layaway account, and will receive a $15 Walmart gift card if they complete their payments by December 14.

Last year, customers had to pay a $5 fee, there was a $10 cancellation fee, and those who paid in full did not receive any gift card refund. This year's plan has no cancellation fee.

The downpayment of 10 percent or $10, whichever is greater, stays the same. Customers must still spend at least $50 to sign up for layaway, and each item must be priced at $15 or more.

Millions of customers used the service last year and "a distinct majority" of those made their full payments, Mac Naughton said, without disclosing specific figures.

Walmart said it would try to make the process easier for customers this year. After signing up at the service desk, customers at some of the 3,678 stores offering layaway can make payments at cash registers rather than having to go back to the service desk. Walmart will also try to coordinate with shoppers through email or phone calls to set up times to pick up merchandise.

Walmart expanded the variety of products available for layaway, adding small appliances and certain sporting goods to the lineup of toys, electronics and jewelry. Walmart continues to have layaway for jewelry year-round.

Other chains that offer layaway include Sears Holding Corp's Kmart and Toys R Us.

Wal-Mart shares were up 0.4 percent at $72.29 on Monday morning on the New York Stock Exchange.